Investigation of a new kind of in-situ measurement method of thermal resistance of building envelope

Abstract

Accurate and effective in-situ measurements of the thermal performance of the building envelope are important for determining the energy use and thermal comfort of buildings. This study proposes a new method, i.e. removing the heat storage effect and heat flow meter method (RHS-HFM) that can eliminate the effects of thermal inertia. And verifies its feasibility by means of the temperature-controlled box method (TCB-HFM) and in-situ measurements of the thermal resistance of walls under four different conditions. The measurement results show that the new method gives reasonable results compared with the TCB-HFM, with a deviation of only 6%; moreover, the error between the thermal resistance obtained with the new method and the design value is only about 7% under any test conditions, it is a good proof of the reliability of the method and its ability to overcome seasonal limitations. It can also be found that the RHS-HFM can effectively shorten about 24 h test period, the new method can greatly improve the measurement efficiency compared to the heat flow meter method. In addition, to further investigate the applicability of the RHS-HFM, the effect of air conditioning is also analyzed in this paper. In summary, the new method proposed in this study can effectively solve the problems of poor accuracy, seasonal limitations and long test cycles in the heat flow meter method, and can provide a better research basis for related studies.